Switching device for a tandem-type magazine feeding system



y 7, 1965 F. P. REED 3,196,568

SWITCHING DEVICE FOR A TANDEM-TYPE MAGAZINE FEEDING SYSTEM Filed Jan. 7, 1964 3 Sheets-Sheet 1 i INVENTOR. :1 FTEElETiEkEREEfi. BY- m j I 6 M .1411, 5

W 50.2 MA? a. a e z d July 27, 1965 F. P. R D 3,196,568

SWITCHING DEVICE FOR A TANDEM-TYPE MAGAZINE FEEDING SYSTEM Filed Jan. 7, 1964 3 Sheets-Sheet 2 INVENTOR.

FIEflETinkEReEi July 27, 1965 F. P. REED SWITCHING DEVICE FOR A TANDEM-TYPE MAGAZINE FEEDiNG SYSTEM Filed Jan. 7, 1964 3 Sheets-Sheet 3 EJ'EFEJ- INVENTOR. Fred ETi 13k PIREE 1:1

BYI

United States Patent SWITCHING DEVKCE FOR A TANDEM-TYPE MAGAZKNE FEEDENG SYSTEM Frederick 1. Reed, ELudlloW, Mesa, assignor to the United States of America as represented by the Secretary of the Army Filed Jan. 7, 19nd, Ser. No. 336,327

6 (Cl. 42- in) (Granted under Title 35, US. Code (1952), see. 2&6)

The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to such a tandem-type magazine feed system for firearms as is disclosed in the Patent 3,140,554 for Double Tandem Arranged Magazine Feeding Device to Richard M. Colby, and it has as its object improved means for switching feed from the front to the rear storage unit in the magazine when the next to the last cartridge in the front unit is transferred to the barrel member for discharge and to an improved follower in the front unit which facilitates the transfer of cartridges from the rear to the front unit.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings in which:

FIG. 1 is a longitudinally cross-sectioned view of the rear end of a rifle with a tandem-type magazine installed and shows the bolt in battery position and two cartridges remaining in the front compartment of the magazine;

PEG. 2 is a view taken along line 22 of FIG. 1;

FIG. 3 is a view taken along line 3-3 of FIG. 2;

FIG. 4 is a view taken along line 4-4 of FIG. 3;

FIG. 5 is a view similar to FIG. 3 but shows the depressors actuated to release the cartridges in the rear compartment;

FIG. 6 is a view taken along line 6-6 of FIG. 5;

FIG. 7 is a view similar to MG. 6 but shows the empty magazine partially removed, permitting the depressors to be reset; and

FIG. 8 is a view taken along line 8-8 of FIG. 1.

Shown in the figures is a rifle 12 having a receiver 14 and a barrel 16 with a chamber 18 for receiving a cartridge 29 for discharge. A bolt 21 is disposed in receiver 14 for reciprocation between a battery and a recoil position.

A magazine well 22 for receiving a magazine 24 extends upwardly into receiver 14!. Magazine 24 is of tandem- E type and includes a front compartment 2 5 and a rear compartment 2.8 both of which are adapted to receive a double stack of cartridges 2% alternately arranged in right and left-hand rows according to conventional design. A port 29 provides communication between front compartmerit 26 and rear compartment 28. Cartridges 2% in front compartment 26 are pressed upwardly to a feeding position therein by a follower 3i which is acted against by a spring 31 and the cartridges in rear compartment 28 are pressed upwardly therein to the feeding posit-ion relative thereto by a spring-biased follower 32. A pair of lips 34 extend arcua-tely inward from the sides of front compartment 26 to cooperate with follower 3th for retaining leading cartridge 2b in such compartment in the "ice feeding position ready for pickup by bolt 21 according to conventional design and a pair of lips 36 extend arouately inward from the sides of rear compartment 28 to cooperate similarly with follower 32 for the same purpose. According to the teachings of the above noted patent application by Richard M. Colby, the feeding position cartridge 2% in front compartment 26 is transferred therefrom into chamber 18 by a rammer 38 on the front end of bolt 21 and the feeding position cartridge in rear compartment 28 is transferred onto follower 3b in the front compartment by a feed pawl 44 In this system, cartridges 2% in rear compartment 28 must be held depressed so that the leading cartridge therein is not contactable by feed pawl 49 until the next to the last cartridge in front com artment 26 is transferred to chamber 13. Then, cart-ridges 2b in rear compartment 28 must be released so that the leading cartridge therein is positioned to be transferred by feed pawl 4d from the rear compartment to the front compartment simultaneously with the transfer of the last cartridge in the front compartment into the barrel chamber by rammer 38 during the following cyclic reciprocation of bolt 21.

To achieve this end, a right-hand switch assembly 42 is mounted on the right wall of magazine Well 22 and a left-hand switch assembly 44 is mounted on the left Wall. In order to facilitate the understanding of switch assemblies 42 and 4 5, only the right-hand switch assembly will be described, it being remembered that left-hand switch assembly 44 is similar thereto, and primes of the numerals referring to the elements in the right-hand switch assembly will be applied to like elements in the left-hand switch assembly.

Right-hand switch assembly 3-2 includes a plate 4 6 which is secured to the right wall of magazine well 22. A flange 48 of rectangular configuration in cross-section is longitudinally disposed along the inside wall of plate 46 and spaced rearwardly thereof and in axial alignment therewith is a rear flange 5%. A bore 52 in rear flange is in co-axial alignment with a bore 54 in flange it;

and such bores receive a rod 55.

A depressor 58 is pivotally mounted approximately midway its vertical length on rod 56 between flange 48 and rear flange 50. Flange 43 and rear flange 5d are so located and spaced that depressor 58 is disposed adjacent that section of rear compartment 23 where cases 59 of cartridges 24) are located so as to be actuatable thereagainst .as hereinafter described. Depressor 58 includes a tongue portion as which extends inwardly approximately at right angles respective to the inside of the depressor so as to have blocking contact with case 59 of the leading one of the cartridges 2t when the tongue portion is pivotally displaced inwardly to a blocking position and which is positioned so that when magazine 24- is inserted into magazine well 22 and pressed thereinto, the tongue portion contacts the leading cartridge 26 before the magazine is fully inserted. Thus, during continual insertion of magazine 24, cartridges 2b are depressed so that the l ading one of the cartridges is displaced away from feeding position when the magazine is fully installed. A clearance at in the side of rear compartment 28 permits the blocking contact of tongue portion 60 with the leading cartridge 29 in the rear compartment during insertion of magazine 24. The longitudinal length of tongue 66 is sufficient to hold its contacted cartridge 26 against p votal displacement.

Provided on the outside of depressor 58 is a cam surface 62 which leads outwardly and downwardly to a vertical flat 64 arranged to be spaced from plate 46 and a recess 66 is formed in depressor 58 between rod 56 and such flat. A lower section 68 of depressor 58, which extends below rod 56, is contactable with plate 46 to limit inner displacement of tongue portion 66 when in the blocking position. A spring 69 is operationally disposed between depressor 58 and plate 4-6 for biasing tongue portion 60 outwardly to a release position. Outer displacement of tongue portion 66 to the release position, wherein cartridges are freed for upward movement to locate the leading one thereof in feeding position, is controlled by a lever '70 as hereinafter described. Provided in magazine 24 under clearance 61 is an opening 72 through which lower section 68 of depressor 58 projects when the depressor is pivoted to move tongue portion 6t) into the release position. Opening '72 is provided with an upper edge 73 which has sliding contact with lower section 68 to pivot tongue portion .66 inwardly to the blocking position when magazine 24 is removed from magazine well 2 2 (FIG. 7).

The reason for both right-hand switch assembly 42 and left-hand switch assembly 44 is because of the double stack arrangement of cartridges 20 in rear compartment 28 which requires one on each sid of magazine 24- as leading cartridge 20 may be in either the right or left row of the double stack.

Lever 76 is pivotally mounted approximately midway the length thereof on plate 46 by means of a stud 74 which is located forwardly of depressor 58 and above flange 48. Lever 70 is provided with a front arm 75 having a tang 76 which extends inwardly therefrom so as to be contactable by a lug 78 on follower 32 when all but two of the cartridges 20 have been transferred from front compart- Inent 26, and thereby translates vertical displacement of the follower to pivot displacement of lever '70 when the follower is further displaced upwardly by removal of the next to the last one of the cartridges. Lever 70 also includes a rear arm 80 which, when front arm 75 is located in its downward position, is positioned between flat 64 of depressor 53 and plate 46 to prevent outward displacement of tongue portion '60 from the blocking position. When front arm 75 is elevated by follower 30, rear arm 89 is moved from flat 64 into registry with recess 66, thereby freeing depressor 58 for pivotal displacement by spring 66 assisted by the camming forces produced through the contact of tongue portion with the cylindrical surface of the contacted case 59 to move the tongue portion to the release position. A spring 82 is operationally disposed between lever 7t) and flange 48 for biasing rear arm 80 upwardly and such upper displacement is llmited by contact of a surface 84 on lever 79 with the top side of flange 48.

In conventional double stack-type magazines, the follower is provided with an arcuate hump on one side to properly establish the two rows of alternately positioned cartridges. Such .a design is not practical in the present feed system because every other one of the cartridges 2% in rear compartment 28 would be in alignment with the follower hump in front compartment 26, whereby the hump would interfere with the forward transfer of the cartridges to the front compartment.

Consequently, follower 36 in front compartment 26 is provided with a pivotal positioner 86 the base of which is received by a longitudinal slot 88 symmetrically formed in a flat platform 90. A pin 92 extends longitudinally through the base of positioner 86 and platform 90 for pivotally mounting the positioner thereon. Formed on the bottom of positioner 86 is a flat 94- which is arranged normal to the long axis of the positioner in a cross-section thereof and so as to lie in the same plane as the bottom side of platform 96 when the positioner is vertically disposed relative thereto. The upper end of spring 31 seats against the bottom side of platform 96 and the upper end is provided with a transverse section 96 which has contact with the underside of the platform and with flat 94, whereby the positioner is held resiliently in the upright position and is easily displaced to the right or left by the ogive of cartridge 26 when transferred from rear compartment 23 to front compartment 26. The bias of spring 31 against positioner 86 and the co-relationship of the positioner and lips 34. resiliently hold leading cartridge 26 in front compartment 26 in the feeding position whether the cartridge is in the right or left row. When cartridges 26 are loaded into front compartment 26, the first cartridge loaded thereinto pivots positioner 86 to one side to correctly establish the double row.

Operation When loaded magazine 24 is to be installed in rifle 12, the top end is inserted into magazine well 22 and pressed inwardly. As magazine 24 is pressed inwardly, the leading cartridge 20 in rear compartment 28 makes blocking contact with either right-hand switch assembly 42 or lefthand switch assembly 44 depending upon in which row the leading cartridge is located. Assuming that leading cartridge 20 is in the right row, the cartridge will contact tongue portion 66 and will thereby be held against further displacement as insertion of magazine 24 is continued. Thus, the leading one of the cartridges 26 is held depressed from feeding position when the magazine is fully installed and latched.

When rifle 12 is fired, th cyclic reciprocation of bolt 21 successively transfers cartridges 20 from front compartment 26 into barrel chamber 18 for discharge. When all but two of the cartridges 20 have been transferred from front compartment 26, follower 36 contacts tangs 76 and 76' on depressors 58 and 58', respectively, and thereby, when the next to the last cartridge in the front chamber is transferred therefrom, the resulting upper displacement of the follower by spring 31 elevates front arms 75 and 75'. The elevation of front arms 75 and 75' lowers rear arms 8t) and from blocking contact between fiats 64 and 64' and flanges 48 and 48' into registry with recesses 66 and 66'. Thereby, depressors 58 and 58 are freed so that tongue portions 66 and 60 are displaced outwardly to their release positions by springs 69.

Upon displacement of tongue portion 60 to the release position, cartridges 20 are biased upwardly in rear compartment 28 so that the leading one is located in the feeding position in time to be contacted by feed pawl 40 during the following stroke of bolt 21 from the recoil to the battery position. During such following stroke, the last cartridge 20 in front compartment 26 is transferred into chamber 18 and the leading cartridge in rear compartment 28 is transferred to the front compartment. Cartridge 20 in front compartment 26 has farther to travel than that from rear compartment 28 and, therefore, is picked up first. This provides time for positioner 86 to snap back into normal, vertical position before contact by cartridge 20. Thus, if the last cartridge 20 in front compartment 26 is in the opposite row than the first one in rear compartment 28, positioner 86 is freed to be displaced to the correct position by the cartridge transferred from the rear compartment.

When magazine 24 is to be removed, it is unlatched and pulled downwardly. This downward displacement moves upper edges 73 and 73', respectively, along lower sections 68 and 68' of depressors 58 and 58' so that tongue portions 66 and 60' are moved inwardly to the blocking position and flats 64 and 64' are moved away from flanges 48 and 48', respectively, so that rear arms 80 and 80' are free to be moved upwardly between the flange and fiat by spring '82. Contact of rear arms 80 and 80' with cam surfaces 62 and 62' assures full displacement of depressors 58 and 58'. Thereby, tongue portions 60 and 60' are held in their blocking positions ready to act against leading cartridge 26 in rear compartment 28 of the fresh magazine 24 when installed in rifle 12.

Although a particular embodiment of the invention has been described in detail herein, it is evident that many variations may be devised within the spirit and scope thereof and the following claims are intended to include such variations.

1 claim:

ll. In a firearm, the combination including a receiver having a magazine well, a bolt disposed in said receiver for reciprocation between a battery and a recoil position, a barrel with a chamber for receiving a cartridge for discharge, a magazine for a plurality of cartridges insertable into said magazine well, a front compartment in said magazine for receiving a double stack of the cartridges, 8. rear compartment in the magazine for receiving a double stack of the cartridges, a follower disposed in said front compartment for biasing the cartridges therein to a feeding position relative thereto, said follower including a flat platform, a positioner mounted on said platform so as to be pivotally displaced to one of two alternate positions for locating the cartridges in the double stack alternately in two rows and to be pivotally displaceable by the cartridge transferred from said rear compartment to said front compertinent to prevent interference with such transfer and a flat formed on the base of said positioner, a magazine spring seated against said platform for biasing the cartridges in said front compartment toward the feeding position relative thereto and a transverse section of said magazine spring arranged for joint contact with said platform and said flat for biasing said positioner to a vertically upright position relative to said platform, means in the rear compartment for biasing the cartridges therein to a feeding position relative thereto, a rammer disposed on the bolt for successively transferring the cartridges from the feeding position in the front compartment into the chamber responsive to reciprocation of said bolt, a feed pawl disposed on said bolt for successively transferring the cartridges from the feeding position in said rear compartment to the feeding position in said front compartment, and switch assembly means including a depressor arranged for cont act by the leading one of the cartridges in said rear compartment to depress the leading cartridge from the feeding position therein when said magazine is inserted int-o the magazine well and a lever arranged in cooperation with said depressor and said follower in said front compartment for releasing the leading one of the cartridges in said rear compartment to the feeding position therein when the next to the last one of the cartridges in said front compartment is transferred into the chamber and discharged.

2. The combination as defined in claim 1 and including means for mounting said depressor on said receiver Within the magazine well for pivotal displacement between a blocking position and a release position, means on said lever for releasably blocking displacement of said depressor from the cartridge blocking position, and means for actuating said lever to release said depressor for displacement to the release position when only one of the cartridges in said front compartment remains herein.

3. The combination as defined in claim l and including a tongue portion on said depressor arranged to blockingly contact the leading one of the cartridges in said rear compartment during insertion of said magazine into the magazine well to hold the leading one of the cartridges depressed from the feeding position respective to said rear compartment when said magazine is fully inserted into the magazine well, and a clearance formed in said magazine to permit blocking contact of said tongue portion with the leading one of the cartridges in said rear cornpartment.

The combination as defined in claim 1 and including a rod arranged for pivotally mounting said depressor intermediate the vertical length thereof on said receiver in said magazine well, a tongue portion formed on that portion of said depressor extending above said rod, a lower section of said depressor located below said rod, a spring for biasing said tongue portion to a position to make locking contact with the leading one of the cartridges in said rear compartment for releasably holding the leading cartridge depressed from the feeding position in said rear compartment, means on said lever for preventing displacement of said depressor from the blocking position, and a clearance in said magazine to permit blocking contact of said tongue with the leading one of the cartridges in said rear compartment.

5. The combination as defined in claim 4 and including a hole formed in said magazine to permit extension of said lower section thereinto when said depressor is pivoted to locate said tongue portion in the release position, and an upper edge of said hole arranged for sliding contact with said lower section during removal of said magazine to pivot said depressor so as to displace said tongue portion to the blocking position.

6. The combination as defined in claim d and including a plate for mounting said switch assembly means on said receiver in the magazine well, means for pivotally mounting said lever intermediate the longitudinal length thereof on said plate, a front arm formed on the front end of said lever, a tang fixed to said front arm for contact by said follower to actuate said lever to a depressor release position when the next to the last one of the cartridges in said front compartment is transferred therefrom into the chamber, and wherein said means on said lever for preventing displacement on said depressor from the cartridge blocking position includes a rear arm normally positioned between said plate and said depressor to prevent displacement thereof from the blocking position, and including a recess formed in said depressor so as to have registry with said rear arm when said lever is pivoted by said follower to the depressor release position to release said depressor for displacement to the release position.

References Cited by the Examiner UNITED STATES PATENTS 3,140,554 7/64 Colby 42-48 BENiAMlN A. BORCHELT, Primary Examiner. FREDERICK C. MATTERN, Examiner. 

1. IN A FIREARM, THE COMBINATION INCLUDING A RECEIVER HAVING A MAGAZINE WELL, A BOLT DISPOSED IN SAID RECEIVER FOR RECIPROCATION BETWEEN A BATTERY AND A RECOIL POSITION, A BARREL WITH CHAMBER FOR RECEIVING A CARTRIDGE FOR DISCHARGE, A MAGAZINE FOR A PLURALITY OF CARTRIDGES INSERTABLE INTO SAID MAGAZINE WELL, A FRONT COMPARTMENT IN SAID MAGAZINE FOR RECEIVING A DOUBLE STACK OF THE CARTRIDGES, A REAR COMPARTMENT IN THE MAGAZINE FOR RECEIVING A DOUBLE STACK OF THE CARTRIDGES, A FOLLOWER DISPOSED IN SAID FRONT COMPARTMENT FOR BIASING THE CARTRIDGES THEREIN TO A FEEDING POSITION RELATIVE THERETO, SAID FOLLOWER INCLUDING A FLAT PLATFORM, A POSITIONER MOUNTED ON SAID PLATFORM SO AS TO BE PIVOTALLY DISPLACED TO ONE OF TWO ALTERNATE POSITIONS FOR LOCATING THE CARTRIDGES IN THE DOUBLE STACK ALTERNATELY IN TWO ROWS AND TO BE PIVOTALLY DISPLACEABLE BY THE CARTRIDGE TRANSFERRED FROM SAID REAR COMPARTMENT TO SAID FRONT COMPARTMENT TO PREVENT INTERFERENCE WITH SUCH TRANSFER AND A FLAT FORMED ON THE BASE OF SAID POSITIONER, MAGAZINE SPRING SEATED AGAINST SAID PLATFORM FOR BIASING THE CARTRIDGES IN SAID FRONT COMPARTMENT TOWARD THE FEEDING POSITION RELATIVE THERETO AND A TRANSVERSE SECTION OF SAID MAGAZINE SPRING ARRANGED FOR JOINT CONTACT WITH SAID PLATFORM AND SAID FLAT FOR BIASING SAID POSITIONER TO A VERTICALLY UPRIGHT POSITION RELATIVE TO SAID PLATFORM, MEANS IN THE REAR COMPARTMENT FOR BIASING THE CARTRIDGE THEREIN TO A FEEDING POSITION RELATIVE THERETO, A RAMMER DISPOSED ON THE BOLT FOR SUCCESSIVELY TRANSFERRING THE CARTRIDGES FROM THE FEEDING POSITION IN THE FRONT COMPARTMENT INTO THE CHAMBER RESPONSIVE TO RECIPROCATION OF SAID BOLT, A FEED PAWL DISPOSED ON SAID BOLT FOR SUCCESSIVELY TRANSFERRING THE CARTRIDGES FROM THE FEEDING POSITION IN SAID REAR COMPARTMENT TO THE FEEDING POSITION IN SAID FRONT COMPARTMENT, AND SWITCH ASSEMBLY MEANS INCLUDING A DEPRESSOR ARRANGED FOR CONTACT BY THE LEADING ONE OF THE CARTRIDGE IN SAID REAR COMPARTMENT TO DEPRESS THE LEADING CARTRIDGE FROM THE FEEDING POSITION THEREIN WHEN SAID MAGAZINE IS INSERTED INTO THE MAGAZINE WELL AND A LEVER ARRANGED IN COOPERATION WITH SAID DEPRESSOR AND SAID FOLLOWER IN SAID FRONT COMPARTMENT FOR RELEASING THE LEADING ONE OF THE CARTRIDGES IN SAID REAR COMPARTMENT TO THE FEEDING POSITION THEREIN WHEN THE NEXT TO THE LAST ONE OF THE CARTRIDGES IN SAID FRONT COMPARTMENT IS TRANSFERRED INTO THE CHAMBER AND DISCHARGED. 